Erodibility of soils of the upper rainforest zone, southeastern Nigeria

Abstract

The susceptibility of some soils in the high rainfall zone of Nigeria to soil erosion must be measured regularly for better soil management. A number of techniques have been adopted for the determination of this soil loss parameter. The aim of this study is to determine the soil characteristics that relate significantly to erodibility. Soil samples collected from 0-20 cm depth from 10 different locations in the upper rainforest area were analysed for particle size distribution, water-stable aggregates, exchangeable cations, organic carbon, soil dispersion and aggregating indices. The soils are mainly Acrisols, Nitosols, Gleysols and Ferralsol in the FAO classification while their textures are sands to sandy-clay-loam. They are very unstable in water as reflected in the higher values of WSA >0Á50 mm and the mean-weight diameter that ranged from 0Á50 to 2Á03 mm. The dispersion ratio for the soils are between 0Á26 and 0Á69 while clay dispersion ratio also ranged from 0Á24 to 0Á80. Revised universal soil loss equation (RUSLE) erodibility model values (K) were from 0Á03 to 0Á06 Mg h MJ À1 mm À1 . These parameters can be effectively used in predicting soil erodibility, though their predictability varied in ranking of soil erodibility. In spite of this variability these indices can be used for potential erosion hazard determination by agricultural extension staff to avoid crop failures and other negative influence of soil erosion. The soil parameters are easy to determine and will be a valuable instrument when faster approaches to erosion control measures are required.

Gully Erosion in Southeastern Nigeria: Role of Soil Properties and Environmental Factors

“…It is a measure of a soil's susceptibility to particle detachment and transport by agents of erosion. Igwe [20] remarked that a number of factors such as the physical and the chemical properties of the soil influence erodibility. In southeastern Nigeria, the nature and the long weathering history of the soils parent material evident in the dominance of the clay mineralogy by non-expanding minerals and low soil organic matter concentration due to high mineralization rates and excessive leaching of nutrients could be linked to the worsening situation.…”

Clay Dispersion in Typical Soils of North Cameroon as a Function of Ph and Electrolyte Concentration

“…There is well-established body of knowledge on the negative influences of dispersion of soil colloids on erosion by water (Brubaker et al, 1992;Salako, 2001;Igwe, 2003Igwe, , 2005Kjaergaard et al, 2004aKjaergaard et al, , 2004b. The selective transport of the soil clay fraction during surface runoff can induce significant losses of nutrients as well as contaminants from the field.…”

Erodibility in relation to water-dispersible clay for some soils of eastern Nigeria

“…Some workers have reported the relationship between aggregation and soil properties (Deshpande et al, 1968;Emerson, 1971;Goldberg et al, 1990). In Nigeria some studies have been carried out to relate aggregate stability and soil properties (Ofomata, 1981(Ofomata, , 1985Igwe et al, 1995aIgwe et al, , 1995bIgwe, 2003). Among other soil properties, Oster et al (1980) indicated that soil dispersion depends on the mineralogy of the clay, the chemical composition of the exchangeable cations and the organic composition of the soil solution.…”